These minor changes added up to a power band that was smoother and more controllable for use in an ATV setup. Yamaha didnít tame the engine to slow it down, they actually made it better. Although power comes on strong in the midrange it is still relatively smooth compared to itsí two wheeled cousin. By keeping the Keihin FCR carburetor the YFZ is awarded with the best throttle response ever from an ATV engine. To keep the high revving engine cool a dry sump oil system sits directly in front of the engine holding enough surplus oil to keep the twin cam engine spinning exactly the way it needs to be.
Although the main construction remains a mild steel round tube design the limits have been slightly pushed by adding an aluminum sub-frame. Several other chassis components have been cast from aluminum such as the hubs and swing-arm, which significantly reduce the accepted weight of a production 4 stroke ATV.
The handling is spot-on; in fact it is the most spot on weíve ever seen from Yamaha. The turning radius is a little wide considering just how controllable the machine is. Steering is very predictable and reminds us of an old friend, not the new high tech ATV that it is.
Suspension is top notch for current production ATVs. Each shock is fully adjustable and rebuildable. Settings are dialed in well for the general public but racers may want to add a small amount of sag and a couple clicks of compression to the rear. Any major suspension company can also perform a complete race rebuild on the complete set of shocks for about the price of a front or rear after market shock.